The present invention relates generally to header flotation systems for pull-type crop-treating equipment in the agricultural industry, and particularly to a header flotation system for use with a pull-type agricultural rake.
As a rake is pulled through the field of crop, the rake reel, supported within the basket, is rotated with the tines moving as close to the ground as possible to maximize crop handling. It is a common shortcoming of pull-type rakes to exhibit poor flotation characteristics, and thus frequently the tines contact the ground, often resulting in costly downtime and repairs.
Header flotation is a desirable design characteristic that permits the header to move vertically whenever an obstacle is encountered or the ground is uneven over the length of the header. xe2x80x9cLateralxe2x80x9d flotation is a refinement whereby one end of the header may rise, for example upon encountering uneven ground, without causing the other end to rise as much as the first end, i.e., the header is allowed to follow the contour of the ground. Neither flotation nor lateral flotation are of much importance or value in the operation of equipment unless these features are enhanced by the necessary degree of sensitivity. More specifically, flotation is almost a valueless concept unless the flotation structure, or mechanism, is sufficiently sensitive to quickly react to encounters with obstacles and/or uneven ground.
Many agricultural rakes incorporate a compression spring as part of the basket lifting linkage to assist in raising the rake over obstacles encountered in the field such as rocks, gopher mounds, branches, etc. Attention is directed to U.S. Pat. Nos. 2,829,486; 2,781,626; 2,657,518 and 2,595,788 for examples of compression springs used in such systems. The primary problem encountered when using a compression spring in a flotation system is that it has too large a spring constant to adequately lift the rake basket over an obstacle, so the rake basket does not, in fact, float, as is desirable and was intended for the equipment represented in those patents. A compression spring is also not adjustable for different types of terrain or heavy add-on options, such as castor wheels and additional tines. Thus, the primary drawback of a compression system is that it lacks the necessary sensitivity.
Since flotation is a major feature, and one of the most desirable characteristics of an agricultural rake and other similar agricultural devices, improvements are usually found to be commercially and operationally important.
It would be desirable and beneficial to provide a flotation system for an agricultural rake that would overcome the above-noted disadvantages of known rake flotation systems.
Accordingly, one object of the present invention is to provide an agricultural rake with an improved flotation system that will reduce the frequency of contact of rake tines with the ground and other objects.
Another object of the instant invention is to provide a flotation system for an agricultural rake that employs tension springs rather than compression springs to improve the lateral flotation characteristics of the rake basket.
A further object of the instant invention is to provide an improved tension spring flotation system for use with agricultural rakes and other similar pull-type equipment.
These and other objects, features and advantages are accomplished according to the instant invention by providing an agricultural rake basket flotation system that employs tension springs to support a portion of the weight of the rake basket, toward the lateral ends thereof, thus allowing for a more sensitive and complete response to encounters with obstacles and irregularities in the ground level.